3Com 10014299 manual Forward and Filter, Final bridging address table

292CHAPTER 19: CONFIGURING BRIDGE

Figure 104 Final bridging address table

00e0.fcaa.aaaa	00e0.fcbb.bbbb
Workstation A	Workstation B

	Bridging table
	MAC address	Port
	00e0.fcaa.aaaa	1
00e0.fccc.cccc	00e0.fcbb.bbbb	1
	00e0.fccc.cccc	2
	00e0.fcdd.dddd	2

Workstation C

Bridge port 1		Ethernet segment 1
	00e0.fcdd.dddd
Bridge
Bridge port 2		Workstation D

Ethernet segment 2

Forward and Filter

The bridge will make the decision to forward frames or not (that is, to filter frames) depending on the following three conditions:

■If Workstation A sends an Ethernet frame whose destination is Workstation C, the bridge will detect this frame and learn that Workstation C corresponds to Bridge port 2 by looking up its bridging table. So, it will forward the frame to Bridge port 2, as shown in the following figure.

Figure 105 Forward

00e0.fcaa.aaaa	00e0.fcbb.bbbb
Workstation A	Workstation B
Source address	Destination address
00e0.fcaa.aaaa	00e0.fccc.cccc

Bridging table

MAC address Port

00e0.fcaa.aaaa 1

Bridge port 1

Ethernet segment 1

00e0.fccc.cccc

00e0.fcbb.bbbb 1

00e0.fccc.cccc 2

00e0.fcdd.dddd 2

Workstation C

Bridge 00e0.fcdd.dddd

Forwarding Workstation D

Bridge port 2

Destination address Source address			Ethernet segment 2
	00e0.fccc.cccc	00e0.fcaa.aaaa

Note that the bridge will forward the broadcast or multicast frames received on one port to the other ports.

Given that Workstation A sends an Ethernet frame to Workstation B, the bridge will filter this frame rather than forwarding it, since Workstation B and Workstation A are located on the same physical network segment.